Spring-washer



(No Model.)

H. A. HARVEY.

SPRING WASHER.

No. 329,733. Patented Nov. 3, A1835.

' certain Improvement in* UNI-TED STATES PATENT EEICE.

HAYWARD A. HARVEY, 0E ORANGE, NEW JERSEY.

'SPRING-WASHER.

LSQEIEQATIQN ormngparz o! .Lettera Patent No. 329.738, dared-.Nevember-a, laas.

iApplication tiled September 26, 1885.. Serial No. 178,226. (No model.)

To all whom it may concern:

Be it known thatfl,` HAYWARD A. Hanf VEY, of Orange, New JemeSy, have invented a p pring-Washers for Bolt-Nuts, of which the following is a specication. l

This improvement relates to the -ll-known spring-washers which, being intdioedbe tween a nut and the object through vw is inserted the bolt to which the nut is apprise, and compressed by the screwing home of the nut, are made, by the expansive force thus stored up in them, to exert upon the nut a strong pressure, which' tends to prevent the nut from being unscrewed by the jarring of the object to which the bolt and nut are applied. Washers of this class have heretofore been made in the form of "single convolutions l of helices by radially' slitting one side of an -lannular Washer and bending the slit ends laterally y in opposite directions. Theslit ends have also'been bent laterally, respectively,

in opposite directions, beyond the true helical plane, in order to have them form so-called biting-points.v Springwashers have also been made from a straight bar by coiling it helical-ly. l .Y

Either of these ,methods of manufacture may be employed in carrying ont the present improvement, which consists of a spring-washer having the form of a single convolution of ahelicallycoiled quadrangular bar, and hav. ling a dishing shape, so that its sides, instead of being in a radial direction perpendicular to the axis of the helix, are inclined relatively thereto. By this improvement, `after the washer has so far yielded to compression as `to have acquired the shape of a hollow frustuniof a cone it is capable of being further compressed, and being thereby more or less fiattened. By compression a torsional stress is imposed upon thewinding bar of which the washer is made. The compressed washer, therefore,'in addition to the expansive force which it possesses by reason of its tendencyl to resume its original helical form, also has Astored upin it a torsional force, resulting from its Vtendency to resume its original dishing shape. This-torsional force greatly augments the frictional hold of the washer upon the surfaces of the objects between which it is intersame, and Fig. 4 is a transverse section taken through the line :v w on Fig. 2.

In a spring-washer of ordinary construction there is no dishing; hence in an end View of an ordinary spring-washer there is presented to the observer, as shown in' Fig. 1, -only one surface, a, of the helically-coiled quadrangu-` lar bar of which the washer is composed. --Ink a similar end view of. a dished washer there is presented Yto-theobserver, as shown in Fig.

2, not only thev surface a, but also" the inner'or yconcave side, b, of the winding bar ofwhich the washer is composed.v

In use, the force by which the (lished washerv lis compressed between the n ut and the object through which the bolt is inserted is exerted' on one side against the inner corner, c, at one end of the helically-coiled bar, and upon the other side against the outer corner, d, 'at' the other end of the helically-coiled bar.

There is thus imposed a torsional stress upon4 lthe winding bar. It will also be understood that when the washer has been so far compressed as to bring all-parts of the inner edge, f

a', of the surface a to the same plane, and all parts of the outer edge of the opposite surface into a parallel plane, the compressed dished washer will have the shape of a hollow frustum of a cone, and that the tendency of further compression will be to- Hatten it. The dish- -ing of the washer, therefore, increases its range of compressibility and `resi1ience, an.d also increases the energy with'which it tends to revert toits original form when released from pressure. v

It is not absolutely essential that the dishing of the washer shall be perfectly symmetrical, or that it should lnecessarily extend from one end of the helically-coiled bar to the other.

Variation in the amount of dishing is shown in 111g. 4,'in which, as will be seen, the end of the helieally-cole'dbar'shown inelevaiion has s ingecnvoluti'on ofl al'helicllycoiledylad 4its upper and-lower edges, eand f, les's steeply raug'ularfbar,` and ha'vg disliing shpe,subl

inclined than the upperand` lower edges, ef vstantially asvand for the purposes' .setfot'lh J Y andf, `of the part of :the bar' show-n in sec! ELA. HARVEY.`

- A Witnesses:

15k/jon.v .y .A t. A A I claim asmynvention-f'i' n A 'l I L ADAMS', f. A .spring-Washer forabpltnutl, formed -of a .-H Y R, G'. HOWES. 

